As is known, syringes are provided with a needle for withdrawing from or injecting into a bottle or the like, or a shaped end of a small sucking or discharging tube, a liquid, generally provided with pharmacological properties. To that end, the syringe may be in a free condition and freely coupled to a bottle, or it may be mounted on an apparatus having a latching member at the bottle mouth. Such an apparatus, comprising a sealed chamber in which the needle is usually housed and from which the needle may exit only when the apparatus is firmly mounted on the mouth of a bottle or the like, is disclosed and illustrated in U.S. Pat. No. 4,576,211.
For some applications and cases it may be dangerous or undesirable to allow the syringe to disengage from the body in which it has been coupled. For example, it would be dangerous to detach the syringe from the apparatus disclosed in the above mentioned U.S. patent, or to remove it from the shaped end of an intravenous injection small tube, into which a very dangerous pharmaceutical substance, such as a cytostatic drug, may be injected by the syringe.